Professor Volokh has an interesting post on the Washington Post about using Powerpoint during trial. In the case (State v. Rivera) referenced in Prof. Volokh's post, the prosecutor went over the top with his use of Powerpoint.
I am a big believer in Powerpoint. I have used it both in the courtroom and the classroom. I find it very helpful in maintaining the attention of both students and jurors. I think individuals, especially Digital Natives, are more receptive to visual information that comes to them in an electronic format. I wouldn't do a whole trial by Powerpoint. However, I think it can be quite effective in the Opening and Closing when you are trying to tell a complete story or sum up the facts.
Washington Post: Powerpoint in Opening Statements and Summations to Juries